1. Field of the Invention
This invention relates generally to cosmetic tooth whitening and more particularly to an appliance having a membrane covered soft impressible applicator for even and efficacious delivery of a tooth whitening preparation to buccal surfaces of target teeth.
2. Antecedents of the Invention
Significant advances in the art of tooth whitening have evolved in recent years. Tooth whitening is no longer relegated to the costly and time consuming procedures rendered by the dental practitioner. Various approaches have evolved for practicing tooth whitening procedures without participation of the dental practitioner.
Among the early tooth whitening systems for do-it-yourself usage was a paste or gel containing a hydrogen peroxide or carbamide peroxide constituent. The gel or paste was applied to tooth surfaces by, for example, a toothbrush, a cotton swab, etc.
Unfortunately, such systems failed to provide readily noticeable results, due to a combination of factors including the limited time duration of application as well as the dilution of effective whitening or bleaching constituent within the oral cavity by saliva. Further, gingival surfaces were engaged by the whitening or bleaching constituent, leading to possible gingival initiation or other undesired effects.
Improved tooth whitening procedures included the admixture of conventional toothpaste together with a tooth whitening preparation, as described in U.S. Pat. No. 5,302,374 issued Apr. 12, 1994 and U.S. Pat. No. 5,597,554 issued Jan. 28, 1997 to applicant herein. The employment of such technique resulted in decreased tooth surface wear as well as an increase in the rate of efficacious release of the whitening or bleaching constituent of the tooth whitening preparation.
A further approach at providing an effective delivery system for a tooth whitening preparation on buccal enamel surfaces of target teeth included the system disclosed in U.S. Pat. No. 5,611,687 which issued Mar. 18, 1997 to applicant herein. Such system comprised and applicator for carrying and applying a liquid preparation solely upon buccal surfaces of target teeth, i.e. teeth which are visible when talking, smiling, etc. The liquid preparation was drawn to an applicator tip by capillary action. To administer a coating of the tooth whitening preparation on selected tooth enamel surfaces, the tip was wiped over the surfaces to be treated.
Other attempts for improving the self administration of tooth whitening preparations included utilizing a fitted dental trough which surrounded buccal, occlusal and lingual tooth surfaces, as disclosed in U.S. Pat. No. 5,165,424 issued Nov. 24, 1992. The system disclosed therein did not attain widespread commercial success, perhaps due to the fact that the device was ungainly and impeded speech. It could not, therefore, be worn in any environment wherein social encounters might be anticipated. Further, the device did not assure the administration of tooth whitening preparation on only selected tooth surfaces and only to selected target teeth.
A further approach comprised the utilization of flexible strips preloaded with a tooth whitening preparation, as disclosed in U.S. Pat. No. 5,891,453 issued Apr. 6, 1999. The flexible strips disclosed therein were unable to attain a true impression of the user's buccal dentition; it could not intimately enter interdental crevices, for example. Further, the user was not able to control the concentration of tooth whitening preparation or limit the application to selected target teeth or tooth surfaces. A further disadvantage was that the tooth whitening preparation was often in contact with gingival surfaces, which often led to gingival irritation.